Method and apparatus for terminal in rrc_inactive to perform system information update in mobile wireless communication system

ABSTRACT

A method and apparatus for monitoring paging in a mobile communication system are provided. Method for monitoring paging includes receiving a first message including first paging cycle and second paging cycle from the AMF, receiving a second message including third paging cycle and fourth paging cycle from the base station, receiving a system information including an information related to the support of extended DRX, determining a reference DRX cycle, monitoring paging occasion based on the reference DRX cycle and receiving a short message.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2021-0138400, filed on Oct. 18, 2021, the disclosureof which is incorporated herein by reference in its entirety.

BACKGROUND Technical Field

The present disclosure relates to a method and apparatus for a terminalwith reduced capability in a wireless communication system to obtainsystem information and access a New Radio cell.

Related Art

To meet the increasing demand for wireless data traffic since thecommercialization of 4th generation (4G) communication systems, the 5thgeneration (5G) system is being developed. For the sake of high, 5Gsystem introduced millimeter wave (mmW) frequency bands (e. g. 60 GHzbands). In order to increase the propagation distance by mitigatingpropagation loss in the 5G communication system, various techniques areintroduced such as beamforming, massive multiple-input multiple output(MIMO), full dimensional MIMO (FD-MIMO), array antenna, analogbeamforming, and large-scale antenna. In addition, base station isdivided into a central unit and plurality of distribute units for betterscalability. To facilitate introduction of various services, 5Gcommunication system targets supporting higher data rate and smallerlatency.

Various attempts are being made to apply the 5G communication system tothe IoT network. For example, 5G communication such as sensor network,machine to machine communication (M2M), and machine type communication(MTC) is being implemented by techniques such as beam forming, MIMO, andarray antenna.

The terminal performing the MTC communication requires only limitedperformance compared to a general smart phone, and a terminal havingonly reduced capability for MTC communication is referred to as a RedCapUE. In order to efficiently support RedCap UE in a mobile communicationsystem, there is a need to introduce a new technology to an existingmobile communication system.

SUMMARY

Aspects of the present disclosure are to address the various methods ofmonitoring paging in mobile communication system. Accordingly, an aspectof the present disclosure is to provide a method and an apparatus forreceiving a first message including first paging cycle and second pagingcycle from the AMF, receiving a second message including third pagingcycle and fourth paging cycle from the base station, receiving a systeminformation including an information related to the support of extendedDRX, determining a reference DRX cycle, monitoring paging occasion basedon the reference DRX cycle and receiving a short message.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a diagram illustrating the architecture of an 5G system and aNG-RAN to which the disclosure may be applied;

FIG. 1B is a diagram illustrating a wireless protocol architecture in an5G system to which the disclosure may be applied;

FIG. 2A is a diagram illustrating an example of a bandwidth part.

FIG. 2B is a diagram illustrating an example of a search space and acontrol resource set.

FIG. 3A is a diagram illustrating operations of a terminal and a basestation according to an embodiment of the present invention.

FIG. 3B is a diagram illustrating operations of a terminal and a basestation related to discontinuous reception according to an embodiment ofthe present invention.

FIG. 3C is a diagram illustrating operations of a terminal and a basestation related to system information update according to an embodimentof the present invention.

FIG. 4 is a flow diagram illustrating an operation of a terminal.

FIG. 5A is a block diagram illustrating the internal structure of a UEto which the disclosure is applied.

FIG. 5B is a block diagram illustrating the configuration of a basestation according to the disclosure.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present invention will be described indetail with reference to the accompanying drawings. In addition, in thedescription of the present invention, if it is determined that adetailed description of a related known function or configuration mayunnecessarily obscure the gist of the present invention, the detaileddescription thereof will be omitted. In addition, the terms to bedescribed later are terms defined in consideration of functions in thepresent invention, which may vary according to intentions or customs ofusers and operators. Therefore, the definition should be made based onthe content throughout this specification.

The terms used, in the following description, for indicating accessnodes, network entities, messages, interfaces between network entities,and diverse identity information is provided for convenience ofexplanation. Accordingly, the terms used in the following descriptionare not limited to specific meanings but may be replaced by other termsequivalent in technical meanings.

In the following descriptions, the terms and definitions given in the3GPP standards 5 are used for convenience of explanation. However, thepresent disclosure is not limited by use of these terms and definitionsand other arbitrary terms and definitions may be employed instead.

Table 1 lists the acronyms used throughout the present disclosure.

TABLE 1 Acronym Full name 5GC 5G Core Network ACK Acknowledgement AMAcknowledged Mode AMF Access and Mobility Management Function ARQAutomatic Repeat Request AS Access Stratum ASN.1 Abstract SyntaxNotation One BSR Buffer Status Report BWP Bandwidth Part CA CarrierAggregation CAG Closed Access Group CG Cell Group C-RNTI Cell RNTI CSIChannel State Information DCI Downlink Control Information DRB (user)Data Radio Bearer DRX Discontinuous Reception HARQ Hybrid AutomaticRepeat Request IE Information element LCG Logical Channel Group MACMedium Access Control MIB Master Information Block NAS Non-AccessStratum NG-RAN NG Radio Access Network NR NR Radio Access PBRPrioritised Bit Rate PCell Primary Cell PCI Physical Cell IdentifierPDCCH Physical Downlink Control Channel PDCP Packet Data ConvergenceProtocol PDSCH Physical Downlink Shared Channel PDU Protocol Data UnitPHR Power Headroom Report PLMN Public Land Mobile Network PRACH PhysicalRandom Access Channel PRB Physical Resource Block PSS PrimarySynchronisation Signal PUCCH Physical Uplink Control Channel PUSCHPhysical Uplink Shared Channel RACH Random Access Channel RAN RadioAccess Network RA-RNTI Random Access RNTI RAT Radio Access Technology RBRadio Bearer RLC Radio Link Control RNA RAN-based Notification Area RNAURAN-based Notification Area Update RNTI Radio Network TemporaryIdentifier RRC Radio Resource Control RRM Radio Resource Management RSRPReference Signal Received Power RSRQ Reference Signal Received QualityRSSI Received Signal Strength Indicator SCell Secondary Cell SCSSubcarrier Spacing SDAP Service Data Adaptation Protocol SDU ServiceData Unit SFN System Frame Number S-GW Serving Gateway SI SystemInformation SIB System Information Block SpCell Special Cell SRBSignalling Radio Bearer SRS Sounding Reference Signal SSB SS/PBCH blockSSS Secondary Synchronisation Signal SUL Supplementary Uplink TMTransparent Mode UCI Uplink Control Information UE User Equipment UMUnacknowledged Mode CRP Cell Reselection Priority

Table 2 lists the terminologies and their definition used throughout thepresent disclosure.

TABLE 2 Terminology Definition allowedCG-List List of configured grantsfor the corresponding logical channel. This restriction applies onlywhen the UL grant is a configured grant. If present, UL MAC SDUs fromthis logical channel can only be mapped to the indicated configuredgrant configuration. If the size of the sequence is zero, then UL MACSDUs from this logical channel cannot be mapped to any configured grantconfigurations. If the field is not present, UL MAC SDUs from thislogical channel can be mapped to any configured grant configurations.allowedSCS-List List of allowed sub-carrier spacings for thecorresponding logical channel. If present, UL MAC SDUs from this logicalchannel can only be mapped to the indicated numerology. Otherwise, ULMAC SDUs from this logical channel can be mapped to any configurednumerology. allowedServingCells List of allowed serving cells for thecorresponding logical channel. If present, UL MAC SDUs from this logicalchannel can only be mapped to the serving cells indicated in this list.Otherwise, UL MAC SDUs from this logical channel can be mapped to anyconfigured serving cell of this cell group. Carrier frequency Centerfrequency of the cell. Cell Combination of downlink and optionallyuplink resources. The linking between the carrier frequency of thedownlink resources and the carrier frequency of the uplink resources isindicated in the system information transmitted on the downlinkresources. Cell Group in dual connectivity, a group of serving cellsassociated with either the MeNB or the SeNB. Cell reselection A processto find a better suitable cell than the current serving cell based onthe system information received in the current serving cell Cellselection A process to find a suitable cell either blindly or based onthe stored information Dedicated signalling Signalling sent on DCCHlogical channel between the network and a single UE. discardTimer Timerto control the discard of a PDCP SDU. Starting when the SDU arrives.Upon expiry, the SDU is discarded. F The Format field in MAC subheaderindicates the size of the Length field. Field The individual contents ofan information element are referred to as fields. Frequency layer set ofcells with the same carrier frequency. Global cell identity An identityto uniquely identifying an NR cell. It is consisted of cellIdentity andplmn-Identity of the first PLMN-Identity in plmn-IdentityList in SIB1.gNB node providing NR user plane and control plane protocol terminationstowards the UE, and connected via the NG interface to the 5GC. Handoverprocedure that changes the serving cell of a UE in RRC_CONNECTED.Information element A structural element containing single or multiplefields is referred as information element. L The Length field in MACsubheader indicates the length of the corresponding MAC SDU or of thecorresponding MAC CE LCID 6 bit logical channel identity in MACsubheader to denote which logical channel traffic or which MAC CE isincluded in the MAC subPDU MAC-I Message Authentication Code -Integrity. 16 bit or 32 bit bit string calculated by NR IntegrityAlgorithm based on the security key and various fresh inputs Logical alogical path between a RLC entity and a MAC entity. There are multiplechannel logical channel types depending on what type of information istransferred e.g. CCCH (Common Control Channel), DCCH (Dedicate ControlChannel), DTCH (Dedicate Traffic Channel), PCCH (Paging Control Channel)LogicalChannelConfig The IE LogicalChannelConfig is used to configurethe logical channel parameters. It includes priority,prioritisedBitRate, allowedServingCells, allowedSCS-List,maxPUSCH-Duration, logicalChannelGroup, allowedCG-List etclogicalChannelGroup ID of the logical channel group, as specified in TS38.321, which the logical channel belongs to MAC CE Control Elementgenerated by a MAC entity. Multiple types of MAC CEs are defined, eachof which is indicated by corresponding LCID. A MAC CE and acorresponding MAC sub-header comprises MAC subPDU Master Cell Group inMR-DC, a group of serving cells associated with the Master Node,comprising of the SpCell (PCell) and optionally one or more SCells.maxPUSCH-Duration Restriction on PUSCH-duration for the correspondinglogical channel. If present, UL MAC SDUs from this logical channel canonly be transmitted using uplink grants that result in a PUSCH durationshorter than or equal to the duration indicated by this field.Otherwise, UL MAC SDUs from this logical channel can be transmittedusing an uplink grant resulting in any PUSCH duration. NR NR radioaccess PCell SpCell of a master cell group. PDCP entity The processtriggered upon upper layer request. It includes the initializationreestablishment of state variables, reset of header compression andmanipulating of stored PDCP SDUs and PDCP PDUs. The details can be foundin 5.1.2 of 38.323 PDCP suspend The process triggered upon upper layerrequest. When triggered, transmitting PDCP entity set TX_NEXT to theinitial value and discard all stored PDCP PDUs. The receiving entitystop and reset t-Reordering, deliver all stored PDCP SDUs to the upperlayer and set RX_NEXT and RX_DELIV to the initial value PDCP-config TheIE PDCP-Config is used to set the configurable PDCP parameters forsignalling and data radio bearers. For a data radio bearer,discardTimer, pdcp-SN-Size, header compression parameters, t-Reorderingand whether integrity protection is enabled are configured. For asignaling radio bearer, t-Reordering can be configured PLMN ID Check theprocess that checks whether a PLMN ID is the RPLMN identity or an EPLMNidentity of the UE. Primary Cell The MCG cell, operating on the primaryfrequency, in which the UE either performs the initial connectionestablishment procedure or initiates the connection re-establishmentprocedure. Primary SCG Cell For dual connectivity operation, the SCGcell in which the UE performs random access when performing theReconfiguration with Sync procedure. priority Logical channel priority,as specified in TS 38.321. an integer between 0 and 7. 0 means thehighest priority and 7 means the lowest priority PUCCH SCell a SecondaryCell configured with PUCCH. Radio Bearer Logical path between a PDCPentity and upper layer (i.e. SDAP entity or RRC) RLC bearer RLC and MAClogical channel configuration of a radio bearer in one cell group. RLCbearer The lower layer part of the radio bearer configuration comprisingthe RLC configuration and logical channel configurations. RX_DELIV Thisstate variable indicates the COUNT value of the first PDCP SDU notdelivered to the upper layers, but still waited for. RX_NEXT This statevariable indicates the COUNT value of the next PDCP SDU expected to bereceived. RX_REORD This state variable indicates the COUNT valuefollowing the COUNT value associated with the PDCP Data PDU whichtriggered t-Reordering. Serving Cell For a UE in RRC_CONNECTED notconfigured with CA/DC there is only one serving cell comprising of theprimary cell. For a UE in RRC_CONNECTED configured with CA/DC the term‘serving cells’ is used to denote the set of cells comprising of theSpecial Cell(s) and all secondary cells. SpCell primary cell of a masteror secondary cell group. Special Cell For Dual Connectivity operationthe term Special Cell refers to the PCell of the MCG or the PSCell ofthe SCG, otherwise the term Special Cell refers to the PCell. SRBSignalling Radio Bearers” (SRBs) are defined as Radio Bearers (RBs) thatare used only for the transmission of RRC and NAS messages. SRB0 SRB0 isfor RRC messages using the CCCH logical channel SRB1 SRB1 is for RRCmessages (which may include a piggybacked NAS message) as well as forNAS messages prior to the establishment of SRB2, all using DCCH logicalchannel; SRB2 SRB2 is for NAS messages and for RRC messages whichinclude logged measurement information, all using DCCH logical channel.SRB2 has a lower priority than SRB1 and may be configured by the networkafter AS security activation; SRB3 SRB3 is for specific RRC messageswhen UE is in (NG)EN-DC or NR-DC, all using DCCH logical channel SRB4SRB4 is for RRC messages which include application layer measurementreporting information, all using DCCH logical channel. Suitable cell Acell on which a UE may camp. Following criteria apply The cell is partof either the selected PLMN or the registered PLMN or PLMN of theEquivalent PLMN list The cell is not barred The cell is part of at leastone TA that is not part of the list of “Forbidden Tracking Areas forRoaming” (TS 22.011 [18]), which belongs to a PLMN that fulfils thefirst bullet above. The cell selection criterion S is fulfilled (i.e.RSRP and RSRQ are better than specific values t- Tinier to control thereordering operation of received PDCP packets. Upon Reordering expiry,PDCP packets are processed and delivered to the upper layers. TX_NEXTThis state variable indicates the COUNT value of the next PDCP SDU to betransmitted. UE Inactive AS UE Inactive AS Context is stored when theconnection is suspended and Context restored when the connection isresumed. It includes information below. the current KgNB and KRRCintkeys, the ROHC state, the stored QoS flow to DRB mapping rules, theC-RNTI used in the source PCell, the cellIdentity and the physical cellidentity of the source PCell, the spCellConfigCommon withinReconfigurationWithSync of the NR PSCell (if configured) and all otherparameters configured except for: parameters withinReconfigurationWithSync of the PCell; parameters withinReconfigurationWithSync of the NR PSCell, if configured; parameterswithin MobilityControlInfoSCG of the E-UTRA PSCell, if configured;servingCellConfigCommonSIB;

In the present invention, “trigger” or “triggered” and “initiate” or“initiated” may be used in the same meaning.

In the present invention, a terminal with reduced capability and RedCapUE may be used in the same meaning.

FIG. 1A is a diagram illustrating the architecture of an 5G system and aNG-RAN to which the disclosure may be applied.

5G system consists of NG-RAN 1A-01 and 5GC 1A-02. An NG-RAN node iseither:

-   -   a gNB, providing NR user plane and control plane protocol        terminations towards the UE; or    -   an ng-eNB, providing E-UTRA user plane and control plane        protocol terminations towards the UE.

The gNBs 1A-05 or 1A-06 and ng-eNBs 1A-03 or 1A-04 are interconnectedwith each other by means of the Xn interface. The gNBs and ng-eNBs arealso connected by means of the NG interfaces to the 5GC, morespecifically to the AMF (Access and Mobility Management Function) and tothe UPF (User Plane Function). AMF 1A-07 and UPF 1A-08 may be realizedas a physical node or as separate physical nodes.

A gNB 1A-05 or 1A-06 or an ng-eNBs 1A-03 or 1A-04 hosts the functionslisted below.

Functions for Radio Resource Management such as Radio Bearer Control,Radio Admission Control, Connection Mobility Control, Dynamic allocationof resources to UEs in uplink, downlink and sidelink(scheduling); and

IP and Ethernet header compression, uplink data decompression andencryption of user data stream; and

Selection of an AMF at UE attachment when no routing to an MME can bedetermined from the information provided by the UE; and

Routing of User Plane data towards UPF; and

Scheduling and transmission of paging messages; and

Scheduling and transmission of broadcast information (originated fromthe AMF or O&M); and

Measurement and measurement reporting configuration for mobility andscheduling; and

Session Management; and

QoS Flow management and mapping to data radio bearers; and

Support of UEs in RRC_INACTIVE state; and

Radio access network sharing; and

Tight interworking between NR and E-UTRA; and

Support of Network Slicing.

The AMF 1A-07 hosts the functions such as NAS signaling, NAS signalingsecurity, AS security control, SMF selection, Authentication, Mobilitymanagement and positioning management.

The UPF 1A-08 hosts the functions such as packet routing and forwarding,transport level packet marking in the uplink, QoS handling and thedownlink, mobility anchoring for mobility etc.

FIG. 1B is a diagram illustrating a wireless protocol architecture in an5G system to which the disclosure may be applied.

User plane protocol stack consists of SDAP 1B-01 or 1B-02, PDCP 1B-03 or1B-04, RLC 1B-05 or 1B-06, MAC 1B-07 or 1B-08 and PHY 1B-09 or 1B-10.Control plane protocol stack consists of NAS 1B-11 or 1B-12, RRC 1B-13or 1B-14, PDCP, RLC, MAC and PHY.

Each protocol sublayer performs functions related to the operationslisted in the table 3.

TABLE 3 Sublayer Functions NAS authentication, mobility management,security control etc RRC System Information, Paging, Establishment,maintenance and release of an RRC connection, Security functions,Establishment, configuration, maintenance and release of SignallingRadio Bearers (SRBs) and Data Radio Bearers (DRBs), Mobility, QoSmanagement, Detection of and recovery from radio link failure, NASmessage transfer etc. SDAP Mapping between a QoS flow and a data radiobearer, Marking QoS flow ID (QFI) in both DL and UL packets. PDCPTransfer of data, Header compression and decompression, Ciphering anddeciphering, Integrity protection and integrity verification,Duplication, Reordering and in-order delivery, Out-of-order deliveryetc. RLC Transfer of upper layer PDUs, Error Correction through ARQ,Segmentation and re-segmentation of RLC SDUs, Reassembly of SDU, RLCre-establishment etc. MAC Mapping between logical channels and transportchannels, Multiplexing/demultiplexing of MAC SDUs belonging to one ordifferent logical channels into/from transport blocks (TB) deliveredto/from the physical layer on transport channels, Scheduling informationreporting, Priority handling between UEs, Priority handling betweenlogical channels of one UE etc. PHY Channel coding, Physical-layerhybrid-ARQ processing, Rate matching, Scrambling, Modulation, Layermapping, Downlink Control Information, Uplink Control Information etc.

A reduced capability UE or RedCap UE has lower performance than ageneral UE and is used in limited scenarios such as IOT. Compared to atypical terminal having a bandwidth of 100 MHz, a transmission/receptionspeed of several Gbps, and four or more Rx processing units (Rxbranches), RedCap terminals have a bandwidth of 20 MHz, atransmission/reception speed of several tens of Mbps, and two or less Rxprocessing units.

The present invention provides a method and apparatus for a RedCap UE toaccess a cell supporting RedCap, receive system information, and performnecessary operations. In particular, the terminal applies search space 0(Search Space 0, hereinafter SS #0) and control resource set 0 (ControlResource Set 0, hereinafter CORESET #0) in the initial bandwidth part(IBWP) to obtain system information.

FIG. 2A is a diagram illustrating an example of a bandwidth part.

With Bandwidth Adaptation (BA), the receive and transmit bandwidth of aUE need not be as large as the bandwidth of the cell and can beadjusted: the width can be ordered to change (e.g. to shrink duringperiod of low activity to save power); the location can move in thefrequency domain (e.g. to increase scheduling flexibility); and thesubcarrier spacing can be ordered to change (e.g. to allow differentservices). A subset of the total cell bandwidth of a cell is referred toas a Bandwidth Part (BWP) and BA is achieved by configuring the UE withBWP(s) and telling the UE which of the configured BWPs is currently theactive one.

FIG. 2A describes a scenario where 3 different BWPs are configured:

-   -   BWP1 with a width of 40 MHz and subcarrier spacing of 15 kHz;        2A-11 or 2A-19    -   BWP2 with a width of 10 MHz and subcarrier spacing of 15 kHz;        2A-13 or 2A-17    -   BWP3 with a width of 20 MHz and subcarrier spacing of 60 kHz.        2A-15

FIG. 2B is a diagram illustrating an example of a search space and acontrol resource set.

A plurality of SSs may be configured in one BWP. The UE monitors PDCCHcandidates according to the SS configuration of the currently activeBWP. One SS consists of an SS identifier, a CORESET identifierindicating the associated CORESET, the period and offset of the slot tobe monitored, the slot unit duration, the symbol to be monitored in theslot, the SS type, and the like. The information may be explicitly andindividually configured or may be configured by a predetermined indexrelated to predetermined values.

One CORESET consists of a CORESET identifier, frequency domain resourceinformation, symbol unit duration, TCI state information, and the like.

Basically, it can be understood that CORESET provides frequency domaininformation to be monitored by the UE, and SS provides time domaininformation to be monitored by the UE.

CORESET #0 and SS #0 may be configured in the IBWP. One CORESET and aplurality of SSs may be additionally configured in the IBWP. Uponreceiving the MIB 2B-01, the UE recognizes CORESET #0 2B-02 and SS #02B-03 for receiving SIB1 using predetermined information included in theMIB. The UE receives SIB1 2B-05 through CORESET #0 2B-02 and SS #02B-03. In SIB1, information constituting CORESET #0 2B-06 and SS #02B-07 and information constituting another CORESET, for example, CORESET#n 2B-11 and SS #m 2B-13 may be included.

The terminal receives necessary information from the base station beforethe terminal enters the RRC_CONNECTED state, such as SIB2 reception,paging reception, and random access response message reception by usingthe CORESETs and SSs configured in SIB1. CORESET #0 2B-02 configured inMIB and CORESET #0 2B-06 configured in SIB1 may be different from eachother, and the former is called a first CORESET #0 and the latter iscalled a second CORESET #0. SS #0 2B-03 configured in MIB and SS #02B-07 configured in SIB1 may be different from each other, and theformer is referred to as a first SS #0 and the latter is referred to asa second SS #0. SS #0 and CORESET #0 configured for the RedCap terminalare referred to as a third SS #0 and a third CORESET #0. The first SS#0, the second SS #0, and the third SS #0 may be the same as ordifferent from each other. The first CORESET #0, the second CORESET #0,and the third CORESET #0 may be the same as or different from eachother. SS #0 and CORESET #0 are each indicated by a 4-bit index. The4-bit index indicates a configuration predetermined in the standardspecification. Except for SS #0 and CORESET #0, the detailedconfiguration of the remaining SS and CORSESET is indicated by eachindividual information element.

When the RRC connection is established, additional BWPs may beconfigured for the UE.

FIG. 3A is a diagram illustrating operations of a terminal and a basestation according to an embodiment of the present disclosure.

In a network consisting of a RedCap UE 3A-01, a base station 3A-03 andan AMF 3A-05, the RedCap UE receives system information, determineswhether to bar a cell, performs cell reselection, monitors a pagingmessage, selects and applies cell common configuration information andtransmits and receives RRC control messages.

In step 3A-11, the RedCap UE camps on a cell managed by the base stationby performing cell selection or cell reselection. The RedCap UE selectsa cell having a good reception signal from among cells of the highestpriority frequency in consideration of cell reselection priority and thelike.

In step 3A-13, the RedCap UE receives the MIB in the selected cell.

The MIB includes controlResourceSetZero, which is a 4-bit indexindicating the configuration of the first CORESET #0, andcontrolResourceSetZero, which is a 4-bit index, indicating theconfiguration of the first SS #0. The UE receives SIB1 by applying thefrequency domain and time pattern indicated by the first CORESET #0 andthe first SS #0.

The MIB includes cellBarred, which is 1-bit information indicatingwhether or not 5 the cell is barred. cellBarred indicates either barredor notBarred. The UE uses cellBarred to determine whether to bar thecell.

The MIB includes a first intraFreqReselection that is 1-bit informationfor controlling intra-frequency cell reselection. The firstintraFreqReselection is defined as Enumerated {allowed, notAllowed}.Also called IFRI_MIB.

In steps 3A-15, the RedCap UE receives SIB1. The RedCap UE stores theacquired SIB1. SIB1 includes ServingCellConfigCommon, which is commonconfiguration information of a serving cell, and a secondintraFreqReselection. The second intraFreqReselection is defined asenumerated with one of Allowed and notAllowed. It is also calledIFRI_SIB.

In step 3A-16, the RedCap UE selects one of a plurality of commonconfiguration information included in ServingCellConfigCommon.

The servingCellConfigCommon of SIB1 includes the following information.

TABLE 4 DownlinkConfigCommon This is a common downlink configuration ofthe serving cell. It consists of subfields such as frequencyInfoDL,initialDownlinkBWP, bcch- Config, and pcch-Config. frequencyInfoDL It isa basic parameter of a downlink carrier. It consists of subfields suchas a frequency band list and carrier bandwidth for each SCS.initialDownlinkBWP This is the configuration of the second downlinkIBWP. It consists of subfields such as BWP, PDCCH- ConfigCommon, andPDSCH-ConfigCommon. The first IBWP has a frequency domain correspondingto the first CORESET#0 of the MIB and has subcarrier spacing indicatedby the MIB. The first IBWP is the IBWP indicated by the MIB and used forreceiving SIB1, the second IBWP is the IBWP indicated by the SIB1 andused for receiving the SIB2, paging, random access response message, andthe like. BWP It is IE that configures general parameters of BWP. Itconsists of subfields such as locationAndBandwidth indicating thebandwidth and location of the BWP, and subcarrierSpacing indicating theSCS of the BWP. PDCCH-ConfigCommon It is the cell-specific PDCCHparameters of the BWP. It consists of subfields such ascontrolResourceSetZero, commonControlResourceSet, searchSpaceZero,commonSearchSpaceList, searchSpaceOtherSystemInformation,pagingSearchSpace, and ra-SearchSpace. controlResourceSetZero It isdefined as an integer between 0 and 15. Indicates one of the predefinedCORESET#0 configurations. The controlResourceSetZero included in the MIBcorresponds to the first CORESET#0, and the controlResourceSetZeroincluded in the PDCCH- ConfigCommon of the servingCellConfigCommon ofSIB 1 corresponds to the second CORESET#0. searchSpaceZero It is definedas an integer between 0 and 15. Indicates one of the predefined SS#0configurations. The searchSpaceZero included in the MIB corresponds tothe first SS#0, and the controlResourceSetZero included in thePDCCH-ConfigCommon of the servingCellConfigCommon of SIB1 corresponds tothe second SS#0. commonControlResourceSet A common CORESET defined byControlResourceSet IE. Defines an additional CORESET that can be usedfor paging reception, random access response reception, systeminformation reception, etc. commonSearchSpaceList List of common SSs.The common SS may be used for paging reception, random access responsereception, system information reception, and the like.searchSpaceOtherSystemInformation Defined by the SS identifier IE. If itis 0, the second SS#0 is indicated, and if it is a value other than 0,one of the SSs defined in commonSearchSpaceList is indicated.pagingSearchSpace Defined by the SS identifier IE. If it is 0, thesecond SS#0 is indicated, and if it is a value other than 0, one of theSSs defined in commonSearchSpaceList is indicated. ra-SearchSpaceDefined by the SS identifier IE. If it is 0, the second SS#0 isindicated. If it is a value other than 0, one of the SSs defined in thecommonSearchSpaceList is indicated. PDSCH-ConfigCommon Cell-specificPDSCH parameters of this BWP. It consists of apdsch-TimeDomainAllocationList. The pdsch-TimeDomainAllocationList is alist composed of a plurality of pdsch-TimeDomainAllocations.pdsch-TimeDomainAllocation A time domain relationship between the PDCCHand the PDSCH. It consists of subfields such as K0 andstartSymbolAndLength. K0 is the slot offset between the DCI and thescheduled PDSCH. startSymbolAndLength is an index indicating a validstart symbol and length combination. pcch-Config Configuration relatedto paging. It consists of sub- fields such as the base station pagingperiod, PF- related parameters, and PO-related parameters. bcch-configIt is a configuration related to system information. It consists ofsubfields such as modificationPeriodCoeff indicating the length of themodification period. UplinkConfigCommonSIB This is a common uplinkconfiguration of the serving cell. It consists of subfields such asfrequencyInfoUL, initialUplinkBWP, and timeAlignmentTimerCommon.frequencyInfoUL It is a basic parameter of the uplink carrier. Itconsists of subfields such as a frequency band list and carrierbandwidth for each SCS. initialUplinkBWP This is the configuration ofthe second uplink IBWP. It consists of subfields such as BWP, rach-ConfigCommon, pusch-ConfigCommon, and pucch- ConfigCommon.rach-ConfigCommon This is the cell-specific random access parameter ofthe BWP. It consists of subfields such as prach- ConfigurationIndex,msg1-Frequency Start, preambleReceivedTargetPower, ra- ResponseWindow,preambleTransMax, msg1- SubcarrierSpacing, rsrp-ThresholdSSB, and ra-ContentionResolutionTimer. prach-ConfigurationIndex PRACH configurationindex. One PRACH configuration corresponds to pattern information on aPRACH transmission opportunity in the time domain (informationindicating in which symbol in which slot of which radio frame PRACHtransmission is possible), a transmission format of a preamble, and thelike. msg1-FrequencyStart The offset from PRB0 of the lowest PRACHtransmission opportunity. Information indicating a PRACH transmissionresource in the frequency domain. PRB0 is the lowest frequency PRB amongPRBs of the corresponding carrier. preambleReceivedTargetPower This isthe target power level of the network receiving end. It is a parameterrelated to transmission power control during the random accessprocedure. ra-ResponseWindow The length of the random access responsewindow expressed in the number of slots. preambleTransMax The maximumnumber of random access preamble transmissions msg1-SubcarrierSpacing Itis PRACH's SCS. It is commonly applied to general terminals and RedCapUEs. rsrp-ThresholdSSB SSB selection criteria. The UE performs randomaccess by selecting a preamble corresponding to the selected SSB.ra-ContentionResolutionTimer This is the initial value of the contentionresolution timer. Indicates the number of subframes. pusch-ConfigCommonCell-specific PUSCH parameters of this BWP. It consists of subfieldslike pusch- TimeDomainAllocationList. The pusch-TimeDomainAllocationList is a list composed of a plurality ofpusch-TimeDomainAllocations. pusch-TimeDomainAllocation A time domainrelationship between the PDCCH and the PUSCH. It consists of subfieldssuch as K2 and startSymbolAndLength. K2 is the slot offset between theDCI and the scheduled PUSCH. startSymbolAndLength is an index indicatinga valid combination of start symbol and length. pucch-ConfigCommon Thisis the cell-specific PUCCH parameter of the BWP. It consists ofsubfields such as pucch- ResourceCommon and p0-norminal.pucch-ResourceCommon It is an index corresponding to a cell-specificPUCCH resource parameters. One index corresponds to a PUCCH format, aPUCCH time period, a PUCCH frequency period, a PUCCH code, and the like.p0-norminal This is a power offset applied during PUCCH transmission.Defined as an integer between -202 and 24 in increments of 2. The unitis dBm. timeAlignmentTimerCommon This is a timer applied when the UEperforms random access for RRC connection establishment procedure andRRC connection re-establishment procedure. When the UE receives the RAR,it starts the timer, and stops the timer when contention fails.tdd-UL-DL-ConfigurationCommon Cell specific TDD UL/DL configuration. Itconsists of subfields such as referenceSubcarrierSpacing, pattern1, andpattern2. referenceSubcarrierSpacing This is the reference SCS used todetermine the time domain boundary in the UL-DL pattern. pattern1,pattern2 TDD Uplink Downlink Pattern. It consists of subfields such asdl-UL-TransmissionPeriodicity, nrofDownlinkSlots, nrofDownlinkSymbols,nrofUplinkSlots, and nrofUplinkSymbols. dl-UL-TransmissionPeriodicityIndicates the period of the DL-UL pattern. nrofDownlinkSlots Indicatesthe number of consecutive full DL slots in each DL-UL pattern.nrofDownlinkSymbols Indicates the number of consecutive DL symbols fromthe beginning of the slot following the last full DL slot.nrofUplinkSlots Indicates the number of consecutive full UL slots ineach DL-UL pattern. nrofUplinkSymbols Indicates the number ofconsecutive UL symbols at the last time point of a slot preceding thefirst full UL slot

ServingCellConfigCommon may also include the following information forRedCap UE.

TABLE 5 controlResourceSetZero_RedCap It is defined as an integerbetween 0 and 15. Indicates one of the predefined CORESET#0configurations. It corresponds to the third CORESET #0.searchSpaceZero_RedCap It is defined as an integer between 0 and 15.Indicates one of the predefined SS#0 configurations. It corresponds tothe third SS#0. searchSpaceOtherSystemInformation_RedCap Defined by theSS identifier IE. If it is 0, the third SS#0 is indicateed, if not 0,one of the SSs defined in commonSearchSpaceList is indicateed.ra-SearchSpace_RedCap Defined by the SS identifier IE. If it is 0, thethird SS#0 is indicateed, if not 0, one of the SSs defined incommonSearchSpaceList is indicateed. . prach-ConfigurationIndex_RedCapPRACH configuration index for RedCap. msg1-FrequencyStart_RedCap PRACHtransmission resource information on the frequency domain for RedCappreambleReceivedTargetPower_RedCap The target power level of the networkreceiver for RedCap. ra-ResponseWindow_RedCap Length of the randomaccess response window for RedCap. preambleTransMax_RedCap Maximumnumber of random access preamble transmissions for RedCaprsrp-ThresholdSSB_RedCap SSB selection criteria for RedCap. ra- Initialvalue of the contention resolution timer forContentionResolutionTimer_RedCap RedCap. intraFreqReselection_RedCapControls cell selection/reselection within the frequency of RedCap UEwhen the highest-priority cell is barred. It is 1-bit information and isdefined as Enumerated {Allowed, notAllowed}. Also called IFRI_SIB1.

IFRI_MIB is defined to be present mandatorily and IFRI_SIB1 is definedto be present optionally. This is to ensure backward compatibility ofSIB1.

Instead of defining IEs for RedCap UEs in units of individual IEs, it isalso possible to define configuration information related to RedCap UEsin units of IE sets as follows.

ServingCellConfigCommon of SIB1 includes downlink IBWP configurationinformation and uplink IBWP configuration information.

Downlink IBWP configuration information includes PDCCH-ConfigCommon andPDCCH-ConfigCommon2. PDCCH-ConfigCommon is used by general terminals andRedCap UEs, and PDCCH-ConfigCommon2 is used by RedCap UEs. RedCap UEuses PDCCH-ConfigCommon when only PDCCH-ConfigCommon is included indownlink IBWP configuration information and uses PDCCH-ConfigCommon2when both PDCCH-ConfigCommon and PDCCH-ConfigCommon2 are included.

PDCCH-ConfigCommon includes controlResourceSetZero,commonControlResourceSet, searchSpaceZero, commonSearchSpaceList,searchSpaceOtherSystemInformation, pagingSearchSpace, andra-SearchSpace. PDCCH-ConfigCommon2 includescontrolResourceSetZero_RedCap, commonControlResourceSet_RedCap,searchSpaceZero_RedCap, commonSearchSpaceList_RedCap,ra-SearchSpace_RedCap.

RedCap UE uses controlResourceSetZero and searchSpaceZero ofPDCCH-ConfigCommon if controlResourceSetZero_RedCap andsearchSpaceZero_RedCap are not included in PDCCH-ConfigCommon2. That is,it is considered that the same value as the second SS #0 is configuredfor the third SS #0 and the same value as the second CORESET #0 isconfigured for the third CORESET #0.

The RedCap UE uses the values indicated in the MIB whencontrolResourceSetZero_RedCap and searchSpaceZero_RedCap are notincluded in PDCCH-ConfigCommon2 and controlResourceSetZero andsearchSpaceZero are not included in PDCCH-ConfigCommon. That is, it isconsidered that the same value as the first SS #0 is configured for thethird SS #0 and the same value as the first CORESET #0 is configured forthe third CORESET #0.

RedCap UE uses ra-SearchSpace of PDCCH-ConfigCommon ifra-SearchSpace_RedCap is not included in PDCCH-ConfigCommon2. That is,it is considered that the same value as ra-SearchSpace is set asra-SearchSpace_RedCap. The RedCap UE performs a random access procedureby applying the third SS #0 and the third CORESET #0.

The uplink IBWP configuration information includes PUCCH-ConfigCommonand PUCCH-ConfigCommon2. PUCCH-ConfigCommon is used by general UEs andRedCap UEs, and PUCCH-ConfigCommon2 is used by RedCap UEs. RedCap UEuses PUCCH-ConfigCommon when only PUCCH-ConfigCommon is included inuplink IBWP configuration information, and uses PUCCH-ConfigCommon2 whenboth PUCCH-ConfigCommon and PUCCH-ConfigCommon2 are included.

PUCCH-ConfigCommon2 is used by RedCap UE. PUCCH-ConfigCommon containspusch-TimeDomainAllocationList. PUCCH-ConfigCommon2 containspusch-TimeDomainAllocationList_RedCap.

The uplink IBWP configuration information includes RACH-ConfigCommon andRACH-ConfigCommon2. RACH-ConfigCommon is used by general terminals andRedCap UEs, and RACH-ConfigCommon2 are used by RedCap UEs. RedCap UEuses RACH-ConfigCommon when only RACH-ConfigCommon is included in uplinkIBWP configuration information, and uses RACH-ConfigCommon2 when bothRACH-ConfigCommon and RACH-ConfigCommon2 are included.

RACH-ConfigCommon includes prach-ConfigurationIndex,msg1-FrequencyStart, preambleReceivedTargetPower, ra-ResponseWindow,preambleTransMax, msg1-SubcarrierSpacing, rsrp-ThresholdSSB, andra-ContentionResolutionTimer.

RACH-ConfigCommon2 includes prach-ConfigurationIndex_RedCap,msg1-FrequencyStart_RedCap, preambleReceivedTargetPower_RedCap,ra-ResponseWindow_RedCap, preambleTransMax_RedCap,rsrp-ThresholdSSB_RedCap, ra-ContentionResolutionTimer_RedCap.msg1-SubcarrierSpacing included in RACH-ConfigCommon is applied to bothnormal UEs and RedCap UEs. In other words, the RedCap UE appliesmsg1-FrequencyStart included in RACH-ConfigCommon2 andmsg1-SubcarrierSpacing included in RACH-ConfigCommon when applying msg1frequency-related information.

If RACH-ConfigCommon2 does not contain prach-ConfigurationIndex_RedCap,msg1-FrequencyStart_RedCap, preambleReceivedTargetPower_RedCap,ra-ResponseWindow_RedCap, preambleTransMax_RedCap,msg1-SubcarrierSpacing_RedCap, rsrp-ThresholdSSB_RedCap,ra-ContentionResolutionTimer_RedCap, RedCap UE uses a same values ofprach-ConfigurationIndex, a same values of msg1-FrequencyStart, a samevalues of preambleReceivedTargetPower, a same values ofra-ResponseWindow, a same values of preambleTransMax, a same values ofmsg1-SubcarrierSpacing, a same values of rsrp-ThresholdSSB, a samevalues of ra-ContentionResolutionTimer in RACH-ConfigCommonrespectively.

In another method, the ServingCellConfigCommon of SIB1 includes thefirst downlink IBWP configuration information, the first uplink IBWPconfiguration information, the second downlink IBWP configurationinformation, the second uplink IBWP configuration information, andtdd-UL-DL-ConfigurationCommon. The first downlink IBWP configurationinformation and the first uplink IBWP configuration information areinformation for a terminal with general capability, and the seconddownlink IBWP configuration information and the second uplink IBWPconfiguration information are information for a RedCap UE.tdd-UL-DL-ConfigurationCommon is information that is commonly applied toa UE with general capability and a RedCap UE.

The first uplink IBWP configuration information includespucch-ConfigCommon and timeAlignmentTimerCommon. The second uplink IBWPconfiguration information may include pucch-ConfigCommon_RedCap. Thepucch-ConfigCommon may include a first pucch-ResourceCommon and a firstp0-norminal. The pucch-ConfigCommon_RedCap may include a secondpucch-ResourceCommon and a second p0-norminal. pucch-ConfigCommon isinformation for a normal UE. pucch-ConfigCommon_RedCap is informationfor RedCap UE. timeAlignmentTimerCommon is information commonly appliedto normal UE and RedCap UE.

The RedCap UE transmits the preamble and initiatestimeAlignmentTimerCommon upon reception of the RAR. Upon receiving Msg4, the UE transmits a HARQ ACK by applying a predeterminedpucch-ResourceCommon and a predetermined p0-normal.

If both the second pucch-ResourceCommon and the firstpucch-ResourceCommon exist, the time/frequency/code resource fortransmitting the HARQ ACK is determined by applying the secondpucch-ResourceCommon. If only the first pucch-ResourceCommon exists, thetime/frequency/code resource for transmitting the HARQ ACK is determinedby applying the first pucch-ResourceCommon.

When both the second p0-norminal and the first p0-norminal exist, thesecond p0-norminal is applied to determine a power offset to be appliedto the HARQ ACK. If only the first p0-norminal exists, the power offsetto be applied to the HARQ ACK is determined by applying the firstp0-norminal. If neither the second p0-norminal nor the p0-norminalexist, a power offset to be applied to the HARQ ACK is determined byapplying a predetermined value. The predetermined value may be, forexample, 2 dBm.

In step 3A-17, the RedCap UE determines whether the current cell is abarred cell or an allowed cell, in consideration of MIB and SIB1.

Regarding cell barring, the RedCap UE determines that the current cellis not barred if all of the following conditions are satisfied. Theconditions below are defined so that the RedCap UE camps on the cellonly when it can operate properly in the cell.

<Cell Allowance Conditions>

0: The received MIB's cellBarred is set to notBarred.

1: IFRI_SIB1 exists (or is included) in the received SIB1. This isbecause the absence of IFRI_SIB1 means that the corresponding cell doesnot consider the operation of the RedCap UE, and the presence ofIFRI_SIB1 means that the corresponding cell is a cell that considers theoperation of the RedCap UE.

2: If the current cell is TDD cell, the UE supports one or more of thefrequency bands indicated in the frequencyBandList for downlink in thereceived SIB1 for TDD, or one or more of the frequency bands indicatedin the frequencyBandList for uplink in the received SIB1 for FDD, andthey are not downlink only bands, and

3: The UE supports an uplink channel bandwidth with a maximumtransmission bandwidth configuration fulfilling following conditions: Itis smaller than or equal to the uplink carrierBandwidth indicated inSIB1 and it is wider than or equal to the bandwidth of the initialuplink BWP

4: the UE supports a downlink channel bandwidth with a maximumtransmission bandwidth configuration fulfilling following conditions: Itis smaller than or equal to the downlink carrierBandwidth indicated inSIB1 it is wider than or equal to the bandwidth of the initial downlinkBWP

5: trackingAreaCode is provided in SIB1 for the selected PLMN or theregistered PLMN or PLMN of the equivalent PLMN list

For example, if trackingAreaCode x is included in SIB1 andtrackingAreaCode related to the registered PLMN of the terminal is alsox, condition 5 is satisfied. The trackingAreaCode related to the PLMN isprovided to the terminal by the AMF during the registration procedurewith the terminal.

The RedCap UE, which determines that the current cell is not barred,performs the following operation.

<Operation of Terminal after Receiving SIB1 in Non-Prohibited Cell>

1: Apply the configuration included in the servingCellConfigCommon. Morespecifically, the UE applies the TDD-UL-DL configuration to determine adownlink slot, an uplink slot, a downlink symbol, and an uplink symbol,and applies a PDSCH configuration selected from among a plurality ofPDSCH-ConfigCommon to receive a PDSCH, and applies a PUSCH configurationselected from among a plurality of PUSCH-ConfigCommon to transmit aPUSCH.

2: A specified PCCH configuration is applied. The specified PCCHconfiguration is no SDAP, no PDCP, and RLC TM. A paging message isreceived by applying the PCCH configuration.

3: If a valid SIB is stored, the stored SIB is used, and if a valid SIBis not stored, a related system information message (SI message) isacquired

The UE also receives subsequent system information, for example, SIB2,SIB3, SIB4, etc. in the not barred cell. SIB2 includes parameters forintra-frequency cell reselection. SIB3 includes other parameters forintra-frequency cell reselection. SIB4 contains parameters for cellreselection between frequencies.

The RedCap UE regards the current serving cell as a barred cell in thecases listed in the table below and performs an appropriate operationaccording to the situation.

TABLE 6 Case Situation RedCap UE operation 1 MIB reception failure Thecurrent cell is considered as a barred cell. The current cell isexcluded from cell selection/cell reselection candidates for 300seconds. It is assumed that both IFRI_MIB and IFRI_SIB1 are allowed.That is, neighboring cells of the corresponding frequency may beincluded in the cell selection/cell reselection candidates. 2 Successfulreception of The current cell is considered as a barred cell. MIB withcellBarred set to Excludes the current cell from candidates fornotBarred. cell selection/cell reselection for 300 seconds. SIB1reception failure If the received IFRI_MIB is allowed, IFRI_SIB1 isconsidered as allowed, and neighboring cells of the correspondingfrequency may be included in the cell selection/cell reselectioncandidates. If the received IFRI_MIB is NotAllowed, IFRI_SIB1 is alsoconsidered as NotAllowed, and neighboring cells of the correspondingfrequency are excluded from cell selection/cell reselection candidates.3 Successful reception of The current cell is considered a barred cell.MIB with cellBarred set to Excludes the current cell from candidates forBarred. cell selection/cell reselection for 300 seconds. If the receivedIFRI_MIB is allowed, IFRI_SIB1 is considered as allowed, and neighboringcells of the corresponding frequency may be included in the cellselection/cell reselection candidates. If the received IFRI_MIB isNotAllowed, IFRI_SIB1 is also considered as NotAllowed, and neighboringcells of the corresponding frequency are excluded from the cellselection/cell reselection candidates. The general terminal does notreceive SIB1. The RedCap UE may receive SIB1 instead of referring toIFRI_MIB, and may exclude or include neighboring cells of thecorresponding frequency from cell selection/cell reselection candidatesaccording to the received value of IFRI_SIB1. 4 Successful MIB receptionThe current cell is considered as a barred cell. with cellBarred set toExcludes the current cell from candidates for notBarred. SIB1 receptioncell selection/cell reselection for 300 seconds. without IFRI_SIB1Regardless of the value of the received IFRI_MIB, IFRI_SIB1 may beconsidered as NotAllowed and neighboring cells of the correspondingfrequency may be excluded from cell selection/cell reselectioncandidates. 5 Successfully received MIB The current cell is considered abarred cell. with cellBarred set to Excludes the current cell fromcandidates for notBarred. Received SIB1 cell selection/cell reselectionfor 300 seconds. with IFRI_SIB1 According to the received IFRI_SIBvalue, The bandwidth supported neighboring cells of the corresponding bythe terminal is less than frequency are included or excluded from thecell the bandwidth of the IBWP. selection/cell reselection candidates. 6Successful reception of The current cell is considered a barred cell.MIB with cellBarred set to Excludes the current cell from candidates fornotBarred. Received SIB1 cell selection/cell reselection for 300seconds. with IFRI_SIB1 Regardless of the received IFRI values, both Thebandwidth supported IFRI_MIB and IFRI_SIB1 are considered as by theterminal is greater NotAllowed and neighboring cells of the than orequal to the corresponding frequency are excluded from cell bandwidth ofthe IBWP. selection/cell reselection candidates. There is noTrackingAreaCode matching the TrackingAreaCode received from SIB1.

The reason why the RedCap UE operates as described above is to preventcamp-on in a cell that does not support the RedCap function and toappropriately control whether or not to reselect cells for cells of thesame frequency. If there is no IFRI to be referred to as in case 1, bothIFRIs may be assumed to be a predetermined value and may be operatedaccordingly. Alternatively, if reception of IFRI_SIB1 fails as in case2, IFRI_MIB may be referred to.

The RedCap UE may be given two IFRI parameters: IFRI_MIB and IFRI_SIB1.RedCap UE considers two parameters and determines whether to allowintra-frequency reselection as shown in the table below.

TABLE 7 IFRI_MIB IFRI_SIB1 RedCap UE operation Note Reception ReceptionIFRI_SIB1 is considered as failure failure Allowed Allowed ReceptionIFRI_SIB1 is considered as IFRI_SIB1 considered as the failure Allowedsame value as IFRI_MIB Allowed Not IFRI_SIB1 is considered as It isdetermined that RedCap Present NotAllowed is not supported in thecorresponding frequency. Allowed Allowed IFRI_SIB1 is considered as thereceived IFRI_SIB1 is Allowed applied as it is Allowed NotAllowedIFRI_SIB1 is considered as the received IFRI_SIB1 is NotAllowed appliedas it is NotAllowed Reception IFRI_SIB1 is considered as IFRI_SIB1considered as the failure NotAllowed same value as IFRI_MIB NotAllowedNot IFRI_SIB1 is considered as It is determined that RedCap PresentNotAllowed is not supported in the corresponding frequency. NotAllowedAllowed IFRI_SIB1 is considered as the received IFRI_SIB1 is Allowedapplied as it is NotAllowed NotAllowed IFRI_SIB1 is considered as thereceived IFRI_SIB1 is NotAllowed applied as it is

The RedCap UE applies the received IFRI_SIB1, if both IFRI_MIB andIFRI_SIB1 are received.

The RedCap UE considers that IFRI_SIB1 is Allowed If neither IFRI_MIBnor IFRI_SIB1 are received.

If the RedCap UE receives IFRI_MIB but does not receive IFRI_SIB1, itdetermines IFRI_SIB1 by distinguishing whether SIB1 reception has failedor IFRI_SIB1 is not included in SIB1. If the reception of SIB1 isunsuccessful, the UE considers that IFRI_SIB1 is the same as IFRI_MIB.If SIB1 is received but IFRI_SIB1 is not included, the UE considers thatIFRI_SIB1 is a predetermined value (eg, notAllowed). This is because,since cells of the same frequency in the same region are highly likelyto be configured identically, if IFRI_SIB1 is not provided in thecurrent cell, it is highly likely that IFRI_SIB1 is not provided inother cells as well. Alternatively, If IFRI_SIB1 is preconfigured to beconsidered as Allowed when UE has received SIB1 from the base stationbut IFRI_SIB1 is not included, IFRI_SIB1 is considered as Allowed.

If MIB reception fails, IFRI_MIB cannot be received.

If IFRI_SIB1 is Allowed, the RedCap UE may select or reselect othercells of the same frequency as the barred cell if the cell reselectionselection criteria are fulfilled

If IFRI_SIB1 is NotAllowed, for 300 seconds the RedCap UE does notselect or reselect other cells of the same frequency as the barred cell,and excludes them from candidates for cell selection/reselection.

If IFRI_SIB1 is NotAllowed, the RedCap UE sets the cell reselectionpriority of the frequency of the barred cell for 300 seconds to thelowest priority. The RedCap UE performs cell reselection for frequenciesother than the barred cell frequency. At this time, the RedCap UEperforms cell reselection by applying the cell reselection priorityindicated in the system information received from an NR cell other thanthe first NR cell.

A UE camped on a not barred cell and prepares to perform random accessin order to perform a necessary procedure. The UE refers to the receivedServingCellConfigCommon.

In steps 3A-21, the RedCap UE transmits a preamble to the base station.

If both prach-ConfigurationIndex_RedCap and prach-ConfigurationIndex areincluded in rach-ConfigCommon (or ServingCellConfigCommon), the RedCapUE applies prach-ConfigurationIndex_RedCap to determine a radio frame,subframe, slot, symbol and preamble format in which preambletransmission is possible. If only prach-ConfigurationIndex is includedin rach-ConfigCommon (or in ServingCellConfigCommon), RedCap UEdetermines radio frame, subframe, slot, symbol and preamble format inwhich preamble transmission is possible by applyingprach-ConfigurationIndex.

If both msg1-FrequencyStart_RedCap and msg1-FrequencyStart are includedin rach-ConfigCommon (or ServingCellConfigCommon), the RedCap UE appliesmsg1-FrequencyStart_RedCap to determine a frequency region in whichpreamble transmission is possible. If only msg1-FrequencyStart isincluded in rach-ConfigCommon (or ServingCellConfigCommon), RedCap UEapplies msg1-FrequencyStart to determine a frequency range in whichpreamble transmission is possible.

RedCap UE selects SSB by applying rsrp-ThresholdSSB_RedCap if bothrsrp-ThresholdSSB_RedCap and rsrp-ThresholdSSB are included inrach-ConfigCommon (or in ServingCellConfigCommon). RedCap UE selects SSBby applying rsrp-ThresholdSSB if only rsrp-ThresholdSSB is included inrach-ConfigCommon (or ServingCellConfigCommon). The terminal selects anSSB having the highest received signal strength among SSBs having areceived signal strength higher than the threshold value. The UE selectsa preamble/PRACH transmission opportunity (Occasion) corresponding tothe selected SSB and transmits the preamble.

After transmitting the preamble, the UE monitors whether a random accessresponse message is received during the random access response window,and if not received, retransmits the preamble. As the maximum number ofpreamble retransmissions, the UE applies preambleTransMax_RedCap whenboth preambleTransMax_RedCap and preambleTransMax are included inServingCellConfigCommon, and applies preambleTransMax when onlypreambleTransMax is included. The UE applies msg1-SubcarrierSpacingincluded in rach-ConfigCommon when transmitting the preamble.

One ServingCellConfigCommon may include two prach-ConfigurationIndex,two msg1-FrequencyStart, two rsrp-ThresholdSSB, two preambleTransMax andone msg1-SubcarrierSpacing for Msg1 transmission. One of the twoprach-ConfigurationIndex, one of the two msg1-FrequencyStart, one of thetwo rsrp-ThresholdSSB, and one of the two preambleTransMax apply only toRedCap UEs, and msg1-SubcarrierSpacing is applied to both RedCap UEs andnon-RedCap UEs. Msg 1 is the preamble.

In steps 3A-23, a random access response message is received from thebase station. The random access response message includes informationsuch as an uplink grant for Msg 3 transmission, a time domain allocationindicator, and a temporary identifier of the terminal.

The random access response message is addressed by the RA-RNTI. Theterminal receives a random access response message by monitoring apredetermined SS in a predetermined CORESET in the random access windowtime period.

If ServingCellConfigCommon includes controlResourceSetZero,searchSpaceZero, ra-SearchSpace, controlResourceSetZero_RedCap,searchSpaceZero_RedCap, and ra-SearchSpace_RedCap and Ifra-SearchSpace_RedCap indicates 0, RedCap UE applies 3rd CORESET #0 and3rd SS #0 to RA-Monitor the RNTI and receive a random access responsemessage.

If only controlResourceSetZero, searchSpaceZero, and ra-SearchSpace areincluded in servingCellConfigCommon and If ra-SearchSpace indicates 0,the RedCap UE applies the 2nd CORESET #0 and the 2nd SS #0 to monitorthe RA-RNTI and receive a random access response message.

If controlResourceSetZero, searchSpaceZero, ra-SearchSpace,controlResourceSetZero_RedCap, searchSpaceZero_RedCap, andra-SearchSpace_RedCap are all included in servingCellConfigCommon and ifra-SearchSpace_RedCap indicates a value other than 0, the RedCap UEapplies the SS having the indicated identifier and the CORESETassociated with the SS to monitor RA-RNTI and receive a random accessresponse message.

If only controlResourceSetZero, searchSpaceZero and ra-SearchSpace areincluded in servingCellConfigCommon and if ra-SearchSpace indicates avalue other than 0, the RedCap UE applies the SS having the indicatedidentifier and the CORESET associated with the SS to monitor RA-RNTI andreceive a random access response message.

If both ra-ResponseWindow and ra-ResponseWindow_RedCap are included inServingCellConfigCommon, the RedCap UE determines the length of therandom access response window by applying ra-ResponseWindow_RedCap.

If only ra-ResponseWindow is included in ServingCellConfigCommon, RedCapUE determines the length of the random access response window byapplying ra-ResponseWindow.

Upon receiving the random access response, the RedCap UE startstImeAlignmentTimer and generates a MAC PDU to transmit Msg 3 to the basestation. The MAC PDU includes an uplink RRC control message such asRRCRequest.

In step 3A-25, the RedCap UE transmits Msg 3 to the base station andstarts the contention resolution timer. If servingCellConfigCommoncontains both ra-ConttentionResolutionTimer andra-ContentionResolutionTimer_RedCap, the RedCap UE sets the contentionresolution timer to ra-ContentionResolutionTimer_RedCap. IfservingCellConfigCommon contains only ra-ConttentionResolutionTimer,RedCap UE sets contention resolution timer to ContentionResolutionTimer.

Msg 3 transmission time is determined by the time domain allocationindicator of the random access response message. The RedCap UEdetermines the start time and transmission duration of the PUSCH towhich Msg 3 is to be transmitted according to the PUSCH time domainallocation entry, indicated by a time domain allocation indicator, of aspecific list from among a pusch-TimeDomainAllocationList, a secondpusch-TimeDomainAllocationList and a default list.

In steps 3A-27, the RedCap UE receives Msg 4 from the base station. Msg4 includes a downlink RRC control message such as RRCSetup.

The RedCap UE determines a transmission resource for transmitting theHARQ ACK for Msg 4 by selecting one of the first PUCCH common resourceinformation (pucch-ResourceCommon) and the second PUCCH common resourceinformation (pucch-ResourceCommon).

The RedCap UE determines the nominal power offset to be applied to HARQACK transmission for Msg 4 by selecting one of a nominal power offset(p0-normal) included in the first PUCCH common configuration information(pucch-ConfigCommon) and a nominal power offset (p0-norminal) includedin the second PUCCH common configuration information(pucch-ConfigCommon) and a nominal power offset fixed to a predeterminedvalue.

The RedCap UE and the base station that have transmitted and receivedthe RRCRequest message and the RRCSetup message establish an RRCconnection.

The base station and the AMF may transmit/receive various NAS messagesand control messages to the UE for which the RRC connection isconfigured in steps 3A-31.

The RedCap UE and the base station can exchange configurationinformation and the like through RRC connection, configure a bearer, andthen transmit/receive data.

In ServingCellConfigCommon of SIB1, PDCCH-ConfigCommon2 is locatedbehind PDCCH-ConfigCommon. In ServingCellConfigCommon of SIB1,PUCCH-ConfigCommon2 is located behind PUCCH-ConfigCommon. InServingCellConfigCommon of SIB1, RACH-ConfigCommon2 is located behindRACH-ConfigCommon.

In ServingCellConfigCommon of SIB1, the second downlink IBWPconfiguration information is located behind the first downlink IBWPconfiguration information. In ServingCellConfigCommon of SIB1, thesecond uplink IBWP configuration information is located behind the firstuplink IBWP configuration information. In ServingCellConfigCommon ofSIB1, controlResourceSetZero_RedCap is located behindcontrolResourceSetZero. In ServingCellConfigCommon of SIB1,searchSpaceZero_RedCap is located behind searchSpaceZero. InServingCellConfigCommon of SIB1, ra-SearchSpace_RedCap is located behindra-SearchSpace. The order of various pieces of information is defined asdescribed above in order to maintain backward compatibility with aterminal or a base station of a previous release.

FIG. 3B is a diagram illustrating operations of UE and a base stationrelated to a discontinuous reception operation.

In step 3B-03, UE transmits a registration request message to the AMF.The registration request message includes information related toregistration, for example, information such as a permanent identifier ofUE. The registration request message may also include informationrelated to discontinuous reception. UE may include a desireddiscontinuous cycle in the control message. UE may include twodiscontinuous reception cycles in the control message. The firstdiscontinuous reception cycle has a relatively short value, and thesecond cycle has a relatively long value. The second cycle is alsocalled an extended discontinuous cycle. Since UE including the extendeddiscontinuous cycle in the control message means that UE supports theextended discontinuous cycle, the information requesting the extendeddiscontinuous cycle can be understood as information related to supportfor the discontinuous extension cycle.

Upon receiving the control message, the AMF determines whether to acceptthe registration request of UE using a permanent identifier of UE. Ifthe registration request is accepted, the AMF sends a registrationaccept message to UE.

In step 3B-05, UE receives a registration accept message from the AMF.The message includes information related to the security key, temporaryidentifier information, and the like. The temporary identifier is anidentifier allocated by the core network and has a length of 48 bits.The temporary identifier is valid until a new temporary identifier isallocated and is referred to as a first UE identifier. The message mayalso include two pieces of information related to discontinuousreception in two fields. The first field indicates one of discontinuousreception cycle value not specified (DRX value not specified),discontinuous reception cycle parameter=32 (DRX cycle parameter T=32),discontinuous reception cycle parameter=64, discontinuous receptioncycle parameter=128 and discontinuous reception cycle parameters=256.The second field indicates the extended discontinuous reception cyclelength duration (eDRX cycle length duration) and indicates one of 5.12seconds, 10.24 seconds, 20.48 seconds, 40.96 seconds, 61.44 seconds,81.92 seconds, 102.4 seconds, 122.88 seconds, 143.36 seconds, 163.84seconds, 327.68 seconds. It indicates one of seconds, 655.36 seconds,1310.72 seconds, 2621.44 seconds, 5242.88 seconds, and 10485.76 seconds.The first field is for a normal discontinuous reception cycle, and afirst discontinuous reception value is configured by the first field.The second field relates to the extended discontinuous reception cycle,and a second discontinuous reception value is configured by the secondfield. The discontinuous cycle indicated in the first field and theextended discontinuous cycle indicated in the second field are used todetermine the first UE-specific discontinuous reception value. Thediscontinuous reception cycle parameters 32, 64, 128, and 256 meandiscontinuous reception cycle values of 320 ms, 640 ms, 1280 ms and 2560ms. As shown above, the set of values related to the first field and theset of values related to the second field do not have a common elementand are mutually exclusive. This is because there is no need toconfigure the same discontinuous cycle in the first field and the secondfield.

In step 3B-07, UE transmits UE capability information message to thebase station. The base station may transmit UE capability requestcontrol message to UE, and UE transmits UE capability informationmessage in response thereto. The control message may include informationindicating support for extended discontinuous reception. The extendeddiscontinuous reception support information may be reported for eachradio access technology. For example, the UE may separately includeinformation indicating support for extended discontinuous reception inEUTRA/LTE and information indicating support for extended discontinuousreception in NR. Whether extended discontinuous reception is supportedis information indicating whether extended discontinuous reception issupported in an INACTIVE state.

The base station configures UE based on the capability of UE. The basestation and UE transmit and receive data. When datatransmission/reception is completed, the base 5 station determines torelease the RRC connection with UE.

In step 3B-09, the base station transmits an RRCRelease message to UE.The RRCRelease message includes SuspendConfig IE and SuspendConfigincludes the following information.

<SuspendConfig>

1: Second UE identifier. Identifier of UE that can be included inResumeRequest when state transitions to RRC_CONNECTED. It is 40 bitslong.

2: Third UE identifier. Identifier of UE that can be included inResuemeRequest when state transitions to RRC_CONNECTED. It has a lengthof 24 bits.

3: ran-Paging Cycle. The paging cycle to apply in the RRC_INACTIVEstate. A third discontinuous reception value is configured by the field.

4: ran-NotificationAreaInfo. Configuration information ofran-NotificationArea composed of a list of cells, etc. When theran_NotificationArea is changed, the UE initiates the resumptionprocedure.

5: t380. A timer associated with the cycleic resume procedure.

6. ran-extendedPagingCycle. Extended paging cycle to apply inRRC_INACTIVE state. A fourth discontinuous reception value is configuredby the field.

UE stores various information of the SuspendConfig including the thirddiscontinuous reception value and the fourth discontinuous receptionvalue.

The third discontinuous reception value is one of 32, 64, 128, and 256,and the fourth discontinuous reception value is one of 256, 512, and1024. Both units are radio frames. UE in the INACTIVE state monitorspaging in a specific radio frame called a paging frame. When the normaldiscontinuous reception is configured, UE determines the paging framewith the third discontinuous reception value, and when the extendeddiscontinuous reception is configured, UE determines the paging framewith the fourth discontinuous reception value. When only the thirddiscontinuous reception value is included in SuspendConfig, normaldiscontinuous reception is configured, and when both the third andfourth discontinuous reception values are included, extendeddiscontinuous reception is configured. In the SuspendConfig, the thirddiscontinuous reception value is mandatorily present and the fourthdiscontinuous reception value is optionally present. Since the thirddiscontinuous reception value was defined as mandatory in the previousrelease, it is defined to be mandatorily present in the presentdisclosure to ensure backward compatibility. If both the thirddiscontinuous reception value and the fourth discontinuous receptionvalue exist in SuspendConfig, UE ignores the third discontinuousreception value and uses the fourth discontinuous reception value.

In step 3B-11, the UE moves to a new cell. The UE may reselect aneighboring cell with better radio signal quality by comparing the radiosignal quality of the serving cell and the neighboring cell.Alternatively, a cell having a radio signal quality equal to or greaterthan a predetermined criteria may be selected.

In step 3B-13, the UE receives system information including SIB1 in thenew cell. SIB1 may include the following information.

<SIB1>

1: Identifier of the cell.

2: 1-bit information indicating whether extended discontinuous receptionis allowed. If this information is present in SIB1, it means thatextended discontinuous reception is allowed in the corresponding cell.If this information does not exist in SIB1, it means that extendeddiscontinuous reception is not allowed in the corresponding cell.

3: Default paging cycle. It indicates one of 32, 64, 128, and 256 andthe unit is a radio frame. The length of one radio frame is 10 ms.

4: Parameters related to the modification cycle. It indicates a value of2, 4, 8, or 16.

5: Hyperframe number (HFN). Hyper frame is also called hyper systemframe, and hyper frame number is also called hyper system frame number.

In step 3B-15, UE determines the paging frame.

A paging frame occurs every reference discontinuous reception cycle. Apaging frame is an SFN that satisfies the following equation.

(SFN+PF_offset)mod T=(T div N)*(UE_ID mod N)  [Equation 1]

T is the reference discontinuous reception cycle, and PF_offset and Nare parameters set in SIB1. UE_ID corresponds to the first UEidentifier. Through Equation 1, UEs are distributed among several pagingframes.

UE monitors paging at a paging occasion of the paging frame or at apaging occasion starting from the paging frame. The paging occasion iscomposed of a plurality of consecutive PDCCH monitoring occasions, andthe PDCCH monitoring occasion is a timeslot in which the paging DCI canbe transmitted. One PDCCH monitoring occasion corresponds to onedownlink beam.

In an arbitrary cell, UE in an INACTIVE state and the base stationdetermine the reference discontinuous reception cycle as follows.

If extended discontinuous reception is not applied to the cell, theshortest value among the first UE-specific discontinuous receptionvalue, the second UE-specific discontinuous reception value, and thedefault paging cycle is determined as the reference discontinuousreception cycle.

When extended discontinuous reception is applied to the cell, a secondUE-specific discontinuous reception value is determined as a referencediscontinuous reception cycle.

If the fourth discontinuous reception value is configured for theINACTIVE UE in suspendConfig of the RRCRelease message, and the SIB1 ofthe cell includes information indicating that extended discontinuousreception is allowed, the extended discontinuous reception is applied tothe INACTIVE UE in the cell.

The first UE-specific discontinuous reception value is a seconddiscontinuous reception value if the second discontinuous receptionvalue is a specific value, and a first discontinuous reception value ifthe second discontinuous reception value is not a specific value. Thespecific values are 5.12 seconds and 10.24 seconds, which are the lowestvalues among the second discontinuous reception values. When the seconddiscontinuous reception value exceeds 10.24 seconds, that is, when it isnot a specific value, since it is impossible to specify the paging frameby SFN, the first discontinuous reception value is used as the firstUE-specific discontinuous reception value. The first UE-specificdiscontinuous reception value is a value for the discontinuous receptioncycle of the idle state UE. The idle state UE monitors the paging toreceive the paging generated by the core network.

The second UE-specific discontinuous reception value is a thirddiscontinuous reception value when only the third discontinuousreception value is included in SuspendConfig, and a fourth discontinuousreception value when both the third discontinuous reception value andthe fourth discontinuous reception value are included. The secondUE-specific discontinuous reception value is a value for thediscontinuous reception cycle of UE in an INACTIVE state. The INACTIVEUE monitors the paging to receive the paging generated by the RAN. TheINACTIVE UE also monitors the paging to receive the paging generated bythe core network. Accordingly, the INACTIVE UE determines the referencediscontinuous reception cycle in consideration of the first UE-specificdiscontinuous reception value as well as the second UE-specificdiscontinuous reception value.

The maximum value of the third discontinuous reception value and theminimum value of the fourth discontinuous reception value are equal to256. Accordingly, if the second UE-specific discontinuous receptionvalue is 256, it may be determined by the third discontinuous receptionvalue or may be determined by the fourth discontinuous reception value.The reason the specific discontinuous reception value is defined forboth the normal discontinuous reception and the extended discontinuousreception is to apply different monitoring operations to thediscontinuous reception value. That is, if 256 is configured for normaldiscontinuous reception, UE determines the paging frame in considerationof the default paging cycle, and as a result, a value shorter than 256may be used for the actual discontinuous reception cycle. However, if256 is configured for extended discontinuous reception, the actualdiscontinuous cycle of UE is 256 regardless of the length of the defaultpaging cycle.

After receiving both the first discontinuous reception value and thesecond discontinuous reception value in the registration accept message,and receiving both the third discontinuous reception value and thefourth discontinuous reception value in SuspendConfig of the RRCReleasemessage, UE determines paging frames as follows in an arbitrary cell.

If information indicating that extended discontinuous reception isallowed is not included in SIB1 of the cell, extended discontinuousreception is not applied in the cell, and a paging frame is determinedbased on the first discontinuous reception value, the thirddiscontinuous reception value and the default paging cycle.

If information indicating that extended discontinuous reception isallowed is included in SIB1 of the cell and the second discontinuousreception value is a specific value, extended discontinuous reception isapplied in the cell, paging frame is determined based on the defaultpaging cycle and the second discontinuous reception value and the fourthdiscontinuous reception value.

If information indicating that extended discontinuous reception isallowed is included in SIB1 of the cell and the second discontinuousreception value is not a specific value, extended discontinuousreception is applied in the cell, and a paging frame is determined basedon the fourth discontinuous reception value and the default paging cycleand the first discontinuous reception value and the second discontinuousreception value. If the second discontinuous reception value is neither5.12 second nor 10.24 second, UE receives core network paging only in apaging transmission window. The paging transmission window occursperiodically with a periodicity of the second discontinuous receptionvalue.

In the paging transmission window, UE determines the shortest of thefirst discontinuous reception value, the fourth discontinuous receptionvalue, and the default paging cycle, or the shortest of the firstdiscontinuous reception value and the default paging cycle, as thereference discontinuous reception cycle, and determines the pagingframe.

Outside the paging transmission window, UE determines the fourthdiscontinuous reception value as the reference discontinuous receptioncycle to determine the paging frame.

UE that receives both the first discontinuous reception value and thesecond discontinuous reception value in the registration accept messageand only the third discontinuous reception value in SuspendConfig of theRRCRelease message determines a paging frame in an arbitrary cell asfollows.

If information indicating that extended discontinuous reception isallowed is not included in SIB1 of the cell, extended discontinuousreception is not applied in the cell, and a paging frame is determinedbased on the first discontinuous reception value, the thirddiscontinuous reception value, and the default paging cycle.

If the information indicating that extended discontinuous reception isallowed is included in SIB1 of the cell and the second discontinuousreception value is a specific value, extended discontinuous reception isapplied in the cell, a paging frame is determined based on the defaultpaging cycle and the second discontinuous reception value and the thirddiscontinuous reception value.

If information indicating that extended discontinuous reception isallowed is included in SIB1 of the cell and the second discontinuousreception value is not a specific value, extended discontinuousreception is applied in the cell, and a paging frame is determined basedon the third discontinuous reception value and the default paging cycleand the first discontinuous reception value and the second discontinuousreception value.

In the paging transmission window, UE determines the paging frame bydetermining the shortest value among the first discontinuous receptionvalue, the third discontinuous reception value, and the default pagingcycle as the reference discontinuous reception cycle.

Outside the paging transmission window, UE determines the paging frameby determining the shorter of the third discontinuous reception valueand the default paging cycle as the reference discontinuous receptioncycle.

After receiving the second discontinuous reception value in theregistration accept message and receiving both the third discontinuousreception value and the fourth discontinuous reception value inSuspendConfig of the RRCRelease message, UE determines a paging frame ina cell as follows.

If information indicating that extended discontinuous reception isallowed is not included in SIB1 of the cell, extended discontinuousreception is not applied in the cell, and a paging frame is determinedbased on the third discontinuous reception value and the default pagingcycle.

If information indicating that extended discontinuous reception isallowed is included in SIB1 of the cell and the second discontinuousreception value is a specific value, extended discontinuous reception isapplied in the cell, and a paging frame is determined based on thefourth discontinuous reception value and the default paging cycle.

If information indicating that extended discontinuous reception isallowed is included in SIB1 of the cell and the second discontinuousreception value is not a specific value, extended discontinuousreception is applied in the cell, and a paging frame is determined basedon the second discontinuous reception value and the fourth discontinuousreception value and the default paging cycle.

In the paging transmission window, UE determines the paging frame bydetermining default paging cycle or the shortest value among the fourthdiscontinuous reception value and the default paging cycle as thereference discontinuous reception cycle.

Outside the paging transmission window, UE determines the fourthdiscontinuous reception value as the reference discontinuous receptioncycle to determine the paging frame.

In step 3B-17, UE monitors the paging occasion. The paging occasionconsists of a plurality of PDCCH monitoring occasions. Each PDCCHmonitoring occasion corresponds to a specific downlink beam, and the UEmay monitor the PDCCH monitoring occasion corresponding to the best beamin one paging occasion. Alternatively, multiple PDCCH monitoringoccasions may be monitored to increase the paging reception probability.A paging occasion starts at the paging frame. The PDCCH monitoringoccasion to be monitored by the UE may belong to the paging frame or asubsequent radio frame.

In step 3B-19, UE receives the paging including the first UE identifieror the second UE identifier. The paging including the first UEidentifier is a paging generated in the core network, and the pagingincluding the second UE identifier is a paging generated in the RAN.When the paging generated in the core network is transmitted to theINACTIVE UE, it means that the core network misunderstands the state ofUE as an idle state. UE transitions from the INACTIVE state to the idlestate and selects a new cell. And it monitors paging in the new cell.Upon receiving the paging including the second UE identifier, UEproceeds 5 with the radio resource control connection resumptionprocedure and transitions to the connected state. UE monitors paging inthe cell until it transitions to the connected state.

In step 3B-21, UE determines the paging frame. If paging including thefirst UE identifier is received, UE selects a new cell and determines apaging frame in the new cell. UE discards the third discontinuousreception value and the fourth discontinuous reception value, anddetermines the paging frame based on the first discontinuous receptionvalue, the second discontinuous reception value, and the default pagingcycle. If the paging including the second UE identifier is received, UEdetermines a paging frame based on the first discontinuous receptionvalue, the second discontinuous reception value, the default pagingcycle and one of the third discontinuous reception value and the fourthdiscontinuous reception value, as in steps 3B-15.

In step 3B-23, UE monitors the paging occasion in consideration of thedetermined paging frame.

FIG. 3C is a diagram illustrating operations of UE and a base stationrelated to system information update.

When system information change is required, in order for plurality ofUEs to acquire updated system information at the same time, the basestation changes system information from the start of the modificationcycle or extended discontinuous reception acquisition cycle (eDRXacquisition cycle) and UEs newly acquire system information at thebeginning of the cycle. That the system information has been changed isnotified to UEs through a specific bit of a Short Message transmittedalong with paging.

3B-03, 3B-05, 3B-07, 3B-09, 3B-11, 3B-13, 3B-15, 3B-17 have beendescribed with reference to FIG. 3B.

In step 3C-03, the base station transmits a Short Message to UE. TheShort Message consists of 8 bits, and the MSB is referred to as bit1 andthe LSB is referred to as bit8. Each bit of a Short Message means thefollowing.

TABLE 8 Bit Short Message 1 systemInfoModification If set to 1:indication of a BCCH modification other than SIB6, SIB7 and SIB8.. Thisindication applies to UEs using eDRX cycle equal to or shorter than theBCCH modification cycle or using DRX cycle in the corresponding cell. 2etwsAndCmasIndication If set to 1: indication of an ETWS primarynotification and/or an ETWS secondary notification and/or a CMASnotification. 3 stopPagingMonitoring This bit can be used for onlyoperation with shared spectrum channel access and ifnrofPDCCH-MonitoringOccasionPerSSB-InPO is present. If set to 1:indication that the UE may stop monitoring PDCCH occasion(s) for pagingin this Paging Occasion 4 systemInfoModification-eDRX If set to 1:indication of a BCCH modification other than SIB6, SIB7 and SIB8. Thisindication applies only to UEs using eDRX cycle longer than the BCCHmodification cycle in the corresponding cell. 5-8 Not used

UE receives the Short Message. When the first set of conditions issatisfied, UE applies the system information acquisition procedure fromthe start of the next modification cycle. When the second condition setis satisfied, UE applies the system information acquisition procedurefrom the start of the next extended discontinuous reception acquisitioncycle.

<Satisfying the First Set of Conditions>

1: Receive a Short Message with bit 1 set to 1.

2: One of the conditions below is met

2-1: SIB1 of the corresponding cell does not include the firstinformation related to the extended discontinuous reception

2-2: SIB1 of the cell includes first information related to extendeddiscontinuous reception, and extended discontinuous reception is notconfigured for UE (that is, neither the second discontinuous receptionvalue nor the fourth discontinuous reception value is configured for UE)

2-3: SIB1 of the corresponding cell includes first information relatedto extended discontinuous reception, and extended discontinuousreception is configured for UE (that is, at least one of the seconddiscontinuous reception value and the fourth discontinuous receptionvalue is configured for UE, or at least one of the extendeddiscontinuous reception cycle configured by the core network and theextended discontinuous reception cycle configured by the RAN isconfigured), and the configured discontinuous reception value is equalto or shorter than the modification cycle.

If both 1 and 2-1 are satisfied, or both 1 and 2-2 are satisfied, orboth 1 and 2-3 are satisfied, the first condition set is satisfied.Alternatively, if only condition 1 is satisfied without considering 2-1,2-2, and 2-3, it may be considered that the first condition set issatisfied. In this case, UE using the extended discontinuous receptioncycle leads to the result of unnecessarily acquiring the systeminformation once more.

<Second Condition Set>

1: Receive a Short Message with bit 4 set to 1.

2: SIB1 of the corresponding cell includes first information related toextended discontinuous reception, extended discontinuous reception isconfigured for UE, and the set extended discontinuous reception value islonger than the modification cycle.

If both 1 and 2 are satisfied, the second set of conditions issatisfied. That the extended discontinuous reception is configured forUE may mean that the second discontinuous reception value is configuredfor UE or that the extended discontinuous reception cycle is configuredby the core network. Or, that extended discontinuous reception isconfigured for UE means that one of second discontinuous reception valueand fourth discontinuous reception value is configured for UE, or thatone of the extended discontinuous reception cycle by the core networkand the extended discontinuous reception cycle by the RAN It could meanthat it has been set.

That the configured discontinuous reception value is equal to or shorterthan the modification cycle may mean that the length of the seconddiscontinuous reception value or the extended discontinuous cycleconfigured by the core network is the same as or shorter than themodification cycle. If both the second discontinuous reception value andthe fourth discontinuous reception value are set, the fact that theconfigured discontinuous reception value is equal to or shorter than themodification cycle means that at least one of the second discontinuousreception value and the fourth discontinuous reception value is equal toor shorter than the modification cycle.

That the configured discontinuous reception value is longer than themodification cycle may mean that the length of the second discontinuousreception value or the extended discontinuous cycle configured by thecore network is longer than the modification cycle. If both the seconddiscontinuous reception value and the fourth discontinuous receptionvalue are configured, the configured discontinuous reception valuelonger than the modification cycle means that both the seconddiscontinuous reception value and the fourth discontinuous receptionvalue are longer than the modification cycle.

The first information related to extended discontinuous reception may bean indicator indicating that extended discontinuous reception isallowed. Alternatively, it may be an integer indicating the hyperframenumber.

The hyperframe number is an integer between 0 and 1023 and has a lengthof 10 bits. One hyperframe consists of 1024 system frames between SFN0and SFN1023. SIB1 includes information indicating a system frame numberand a hyperplay number. Hyperframes exist continuously.

The modification cycle has a length multiplied by the default pagingcycle by the modification cycle parameter. The modification cycle existscontinuously, and the radio frame at which each modification cyclestarts is an SFN whose value obtained by modulo operation with themodification cycle length is 0.

The extended discontinuous reception acquisition cycle consists of 1024hyperframes. The length of the hyperframe is 10.24 seconds, and thelength of the extended discontinuous reception acquisition cycle is10485.76 seconds. The hyperframe at which the extended discontinuousreception acquisition cycle starts is a hyperframe number with a valueof 0 obtained by modulo operation with 1024.

When the first condition set or the second condition set is satisfied,UE proceeds to steps 3C-05 at the beginning of the next modificationcycle or the beginning of the next extended discontinuous receptionacquisition cycle.

In step 3C-05, UE applies the system information acquisition procedure.

<System Information Acquisition Procedure>

1: Applying the specified BCCH configuration. For the specified BCCHconfiguration, SDAP configuration is not used, PDCP configuration is notused, and RLC configuration is transparent mode.

2: Acquire the MIB. MIB includes SIB1 scheduling information.

3: Acquire the SIB1. SIB1 includes mapping information between SI andSIB and scheduling information of SI.

4: Acquire SI messages

5: SI request on demand (request on demand system information). UErequests SI that is not broadcast from the base station.

FIG. 4 is a diagram illustrating an operation of a terminal.

In step 4A-01, receiving a first message including a first fieldindicating a first discontinuous period and a second field indicating asecond discontinuous period from the access mobility function;

In step 4A-03, a system information block 1 including an integer relatedto the first period is received from the base station.

In step 4A-05, the first period expressed by the number of radio framesis determined based on the default paging period and an integer relatedto the first period. In step 4A-07, a short message composed of 8 bitsis received.

In step 4A-09, the system information acquisition process is applied.

When the first set of conditions is satisfied, the terminal applies thesystem information acquisition process from the start of the next firstperiod. When the second set of conditions is satisfied, the terminalapplies the system information acquisition process from the start of thenext second period.

If the first bit of the short message is set to 1, the first set ofconditions is satisfied. In addition, when the terminal is configuredwith a discontinuous reception period shorter than or equal to the firstperiod, the first set of conditions is satisfied.

If the second bit of the short message is set to 1, information relatedto extended discontinuous reception is included in the systeminformation block 1, and the terminal is configured with a discontinuousreception period longer than the first period, the second set ofconditions is satisfied.

The length of the first period is set to a variable length of a multipleof the default paging period and the length of the second period isfixed to 1048575 seconds.

In the short message, the first bit is bit 1 and the first bit is bit 4.

The information related to the extended discontinuous reception may beinformation indicating whether the extended discontinuous reception isallowed.

The information related to the extended discontinuous reception may beinformation indicating a hyper system frame number.

The discontinuous reception period is determined based on a firstdiscontinuous reception period, a second discontinuous reception period,and a default paging period.

FIG. 5A is a block diagram illustrating the internal structure of a UEto which the disclosure is applied.

Referring to the diagram, the UE includes a controller 5A-01, a storageunit 5A-02, a transceiver 5A-03, a main processor 5A-04 and I/O unit5A-05.

The controller 5A-01 controls the overall operations of the UE in termsof mobile communication. For example, the controller 5A-01receives/transmits signals through the transceiver 5A-03. In addition,the controller 5A-01 writes and reads data in the storage unit 5A-02. Tothis end, the controller 5A-01 includes at least one processor. Forexample, the controller 5A-01 may include a communication processor CPthat performs control for communication and an application processor APthat controls the upper layer, such as an application program. Thecontroller controls storage unit and transceiver such that UE operationsillustrated in FIG. 3A and FIG. 3B and FIG. 3C and FIG. 4 are performed.

The storage unit 5A-02 stores data for operation of the UE, such as abasic program, an application program, and configuration information.The storage unit 5A-02 provides stored data at a request of thecontroller 5A-01.

The transceiver 5A-03 consists of a RF processor, a baseband processorand plurality of antennas. The RF processor performs functions fortransmitting/receiving signals through a wireless channel, such assignal band conversion, amplification, and the like. Specifically, theRF processor up-converts a baseband signal provided from the basebandprocessor into an RF band signal, transmits the same through an antenna,and down-converts an RF band signal received through the antenna into abaseband signal. The RF processor may include a transmission filter, areception filter, an amplifier, a mixer, an oscillator, adigital-to-analog converter DAC, an analog-to-digital converter ADC, andthe like. The RF processor may perform MIMO and may receive multiplelayers when performing the MIMO operation. The baseband processorperforms a function of conversion between a baseband signal and a bitstring according to the physical layer specification of the system. Forexample, during data transmission, the baseband processor encodes andmodulates a transmission bit string, thereby generating complex symbols.In addition, during data reception, the baseband processor demodulatesand decodes a baseband signal provided from the RF processor, therebyrestoring a reception bit string.

The main processor 5A-04 controls the overall operations other thanmobile operation. The main processor 5A-04 process user input receivedfrom I/O unit 5A-05, stores data in the storage unit 5A-02, controls thecontroller 5A-01 for required mobile communication operations andforward user data to I/O unit 905.

I/O unit 5A-05 consists of equipment for inputting user data and foroutputting user data such as a microphone and a screen. I/O unit 5A-05performs inputting and outputting user data based on the mainprocessor's instruction.

FIG. 5B is a block diagram illustrating the configuration of a basestation according to the disclosure.

As illustrated in the diagram, the base station includes a controller5B-01, a storage unit 5B-02, a transceiver 5B-03 and a backhaulinterface unit 5B-04.

The controller 5B-01 controls the overall operations of the main basestation. For example, the controller 5B-01 receives/transmits signalsthrough the transceiver 5B-03, or through the backhaul interface unit5B-04. In addition, the controller 5B-01 records and reads data in thestorage unit 5B-02. To this end, the controller 5B-01 may include atleast one processor. The controller controls transceiver, storage unitand backhaul interface such that base station operation illustrated inFIG. 3A and FIG. 3B and FIG. 3C are performed.

The storage unit 5B-02 stores data for operation of the main basestation, such as a basic program, an application program, andconfiguration information. Particularly, the storage unit 5B-02 maystore information regarding a bearer allocated to an accessed UE, ameasurement result reported from the accessed UE, and the like. Inaddition, the storage unit 5B-02 may store information serving as acriterion to deter mine whether to provide the UE with multi-connectionor to discontinue the same. In addition, the storage unit 5B-02 providesstored data at a request of the controller 5B-01.

The transceiver 5B-03 consists of a RF processor, a baseband processorand plurality of antennas. The RF processor performs functions fortransmitting/receiving signals through a wireless channel, such assignal band conversion, amplification, and the like. Specifically, theRF processor up-converts a baseband signal provided from the basebandprocessor into an RF band signal, transmits the same through an antenna,and down-converts an RF band signal received through the antenna into abaseband signal. The RF processor may include a transmission filter, areception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC,and the like. The RF processor may perform a down link MIMO operation bytransmitting at least one layer. The baseband processor performs afunction of conversion between a baseband signal and a bit stringaccording to the physical layer specification of the first radio accesstechnology. For example, during data transmission, the basebandprocessor encodes and modulates a transmission bit string, therebygenerating complex symbols. In addition, during data reception, thebaseband processor demodulates and decodes a baseband signal providedfrom the RF processor, thereby restoring a reception bit string.

The backhaul interface unit 5B-04 provides an interface forcommunicating with other nodes inside the network. The backhaulinterface unit 5B-04 converts a bit string transmitted from the basestation to another node, for example, another base station or a corenetwork, into a physical signal, and converts a physical signal receivedfrom the other node into a bit string.

What is claimed is:
 1. A method by a terminal, the method comprising:receiving from a AMF (Access Mobility Function) a first messageincluding a first discontinuous reception cycle and a seconddiscontinuous reception cycle; receiving in a first cell a systeminformation; determining a reference paging cycle; determining a pagingframe based on the reference paging cycle; monitoring in the first cella paging occasion in the paging frame; and receiving in the first cell ashort message, wherein, if a first information related to extendeddiscontinuous reception is included in the system information and thesecond discontinuous reception cycle is shorter than a modificationperiod, the system information acquisition procedure is initiated when abit1 of the short message is set to 1, and wherein, if a firstinformation related to extended discontinuous reception is included inthe system information and the second discontinuous reception cycle islonger than the modification period, the system information acquisitionprocedure is initiated when a bit4 of the short message is set to
 1. 2.The method of claim 1, wherein the modification period is equal toproduct of a first value and a second value, the first value is a valueindicating a default paging cycle and the second value is an integer ofa set of specific integers.
 3. The method of claim 1, wherein theterminal, when the system information acquisition procedure isinitiated, applies a specific BCCH (Broadcast Control Channel)configuration, acquires MIB (Master Information Block) and acquires SIB1(System Information Block1).
 4. A terminal in a wireless communicationsystem, the terminal comprising: a transceiver configured to transmitand receive a signal; and a controller configured to control thetransceiver to: receive from a AMF (Access Mobility Function) a firstmessage including a first discontinuous reception cycle and a seconddiscontinuous reception cycle; receive in a first cell a systeminformation; determine a reference paging cycle; determine a pagingframe based on the reference paging cycle; monitor in the first cell apaging occasion in the paging frame; and receive in the first cell ashort message, wherein, if a first information related to extendeddiscontinuous reception is included in the system information and thesecond discontinuous reception cycle is shorter than a modificationperiod, the system information acquisition procedure is initiated when abit1 of the short message is set to 1, and wherein, if a firstinformation related to extended discontinuous reception is included inthe system information and the second discontinuous reception cycle islonger than the modification period, the system information acquisitionprocedure is initiated when a bit4 of the short message is set to 1.